Vascular leak syndrome (VLS) is characterized by hypotension, peripheral edema and hypoalbuminemia. VLS can occur as a side effect of illness especially illnesses due to pathogens, inter alia, viruses and bacteria. Vascular leak complicates the healing process and can itself be a direct result of certain therapies. For example, patients suffering from malignant renal carcinoma are given Interleukin-2 (IL-2) to help boost their immune system. However, this treatment must be withdrawn in many patients due to the onset of severe VLS well before the full course of treatment can be administered. VLS restricts the doses of IL-2 which can be administered to humans and, in some cases, necessitates the cessation of therapy before the therapy is maximally effective.
VLS is characterized by an increase in vascular permeability accompanied by extravasation of fluids and proteins resulting in interstitial edema and organ failure. Manifestations of VLS include fluid retention, increase in body weight, peripheral edema, pleural and pericardial effusions, ascites, anasarca and, in severe form, signs of pulmonary and cardiovascular failure. Symptoms are highly variable among patients and the causes are poorly understood. Endothelial cell modifications or damage are thought to be important is vascular leak. The pathogenesis of endothelial cell (EC) damage is complex and can involve activation or damage to ECs and leukocytes, release of cytokines and of inflammatory mediators, alteration in cell-cell and cell-matrix adhesion and in cytoskeleton function.
One of the most frightening aspects of cancer is its ability to spread, or metastasize. Initially, cancer cells are found grouped together thereby forming one or more tumors. After formation of the primary tumor, cancer cells can gain the ability to separate from the original tumor and travel to other areas of the body. Lung cancer cells that take up in the liver and form tumors are still lung cancer cells. Thus, the propensity for one particular form of cancer to metastasize is dependent on many factors, including type of cancer; however, the overall process of how cells begin the process of metastasis is still not completely understood.
If a single localized tumor is discovered before it has had a chance to metastasize, then the prognosis of patient survival is higher. This is because the tumor can be effectively excised or destroyed by radiation or chemotherapy. There is, therefore, a difference between tumor growth and metastasis of the tumor cells; the first does not always lead to the other. Cancers that have metastasized, however, are difficult to cure because of extent to which they have spread throughout the body.
In order to metastasize, a cancer cell must break away from its tumor and invade either the circulatory or lymph system. The free cells are then carried to a new location where they establish themselves. Although the body has natural safeguards that prevent cell from surviving after being detached from their natural location, some cancer cells have the ability to overcome these safeguards. Therefore, if metastasis is stopped or significantly reduced, the extent of cancer can be determined and subsequently treated. As such, a follow up treatment to cancer therapy wherein a tumor has been excised or radiation/chemotherapy has been used, would be the treatment of the patient to an anti-metastasizing agent. There is a long felt need for methods of preventing cancer cell metastasis.
The growth of primary tumors also presents a challenge to treatment. If the growth of a primary tumor goes unchecked, the initial tumor can grow to a size that adversely effects organ function at the primary site and in nearby tissues. Metastasis of the primary tumor are also more likely if the primary tumor's growth is uncontrolled. There is a need for methods of slowing or preventing tumor growth.
During the course of antiviral and antibacterial infections, patients can develop vascular leak that is induced as result of the initial infection. There is now a long felt need for a method of preventing vascular leak due to viral or bacterial infection, and for providing methods of increasing the survival of humans or other mammals infected with one or more pathogens. In addition, there is a long felt need for a method of preventing vascular leakage due to certain anticancer drugs or other anticancer therapies such that the administration of anticancer drugs or anticancer therapies can be given to humans or other mammals for a longer course of treatment or therapy.